------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- This program is the Ada implementation of (1+1)-PAES.
-- The original code of (1+1)-PAES is implemented in C
-- available from: http://www.cs.man.ac.uk/~jknowles/multi/
--
------------------------------------------------------------------------------
------------------------------------------------------------------------------



  
package Paes is

  ---------------------
  --    Constants    --
  ---------------------

  MAX_GENES : constant integer := 1000;  -- change as necessary
  MAX_OBJ   : constant integer := 10;    -- change as necessary 
  MAX_ARC   : constant integer := 200;   -- change as necessary
  MAX_LOC   : constant integer := 1000000;--32768; -- number of locations in grid (set for a three-objective problem using depth 5)
  LARGE     : constant integer := 2000000000; -- should be about the maximum size of an integer for your compiler 
  
  ---------------------
  --      Types      --
  ---------------------

  -- This type used to define a chromosome of a solution
  type chrom_type is array(1..MAX_GENES) of integer;

  -- This type used to define objectives of a solution
  type obj_type is array(1..MAX_OBJ) of float;

  type string_type is new string(1..50);

  -- This is the main type used to define solutions
  type solution is
  record
      chrom : chrom_type;
      obj   : obj_type;
      grid_loc : integer;
  end record;

  -- This type is used to define the archive of solutions
  type arc_type is array(1..MAX_ARC) of solution;

  ----------------------
  -- Global variables --
  ----------------------

  
  c   : solution; -- current solution
  m   : solution; -- mutant solution
  arc : arc_type; -- archive of solutions
 
  ------------------------------------------------------------------------------------------------------
  -- depth: this is the number of recursive subdivisions of the objective space carried out in order to 
  --        divide the objective space into a grid for the purposes of diversity maintenance. Values of 
  --        between 3 and 6 are useful, depending on number of objectives.                               
  -- objectives: the number of objectives to the problem.                                               
  -- genes: the number of genes in the chromosome. (Only integer genes can be accepted).                
  -- alleles: the number of values that each gene can take.                                             
  -- archive: the maximum number of solutions to be held in the nondominated solutions archive. 
  -- iterations: the program terminates after this number of iterations.        
  -- minmax: set to 0 (zero) for minimization problems, 1 for maximization problems.
  ------------------------------------------------------------------------------------------------------
  depth,  objectives, genes, archive, iterations, minmax : integer; 

  arclength : integer := 0; -- current length of the archive

  gl_offset  : obj_Type;   -- the range, offset etc of the grid 
  gl_range   : obj_Type;
  gl_largest : obj_Type;
  grid_pop   : array(1..MAX_LOC) of integer;  -- the array holding the population residing in each grid location

  change : integer := 0;


  -----------------------------
  -- Non-generic subprograms --
  -----------------------------

  function compare_min(first : obj_type; second : obj_type; n : integer) return integer;
  function compare_max(first : obj_type; second : obj_type; n : integer) return integer;
  function equal(first : obj_type; second : obj_type; n : integer) return integer;
  procedure print_genome(s : solution);
  procedure print_eval(s : solution);
  procedure add_to_archive(s : solution);
  function compare_to_archive(s : solution) return integer;
  procedure update_grid(s : in out solution);
  procedure archive_soln(s : solution);
  function find_loc(eval : obj_type) return integer;

  -------------------------
  -- Generic subprograms --
  -------------------------
  
  -- User should define mutate, evaluate and init procedures 
  -- according to the MOO problem solved with PAES

  generic
      with procedure customize_mutate (s : in out solution);
  procedure mutate (s : in out solution);

  generic
      with procedure customize_evaluate(s : in out solution);
  procedure evaluate(s : in out solution);

  generic
      with procedure customize_init;
  procedure init;
  
end Paes;